Waste Tire Heat Treatment to Prepare Sulfur Self-Doped Char: Operando Insight into Activation Mechanisms Based on the Char Structures Evolution

Processes

Qing Li¹  Qingwei Hu²  Yi Wang³  Qiangqiang Ren³  Zhiwen Lei³  Limo He³  Sheng Su³  Jun Xiang³  Song Hu³  Long Jiang³ 

[1] School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;Shouyang Mountain Power Plant, Datang Corporation Ltd., Luoyang 471900, China;State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;

关键词: waste tire;    sulfur;    char;    activation;    structure;    specific capacitance;   

DOI  :  10.3390/pr9091622

来源: DOAJ

【 摘 要 】

Waste tire (WT) can be heat-treated to be high-quality sulfur self-doped char via pyrolysis and K₂FeO₄-assisted activation processes. This work aimed at further studying the activation mechanisms based on the char structures evolution by operando experimental method. Activation treatment process (from 50 °C to 800 °C and then held for 3 h) was divided into six typical stages (S1–S6) and consisted of carbonization process (S1–S4) and effective activation process (S4–S6). During the carbonization process, the specific capacitance only increased from 0.2 F/g to 12.4 F/g, aromatic ring systems and alkyl-aryl C-C bonds generated, S 2p_3/2 (sulphide bridge) was mainly gradually consumed. During the effective activation process, the specific capacitance hugely increased from 12.4 F/g to 112.5 F/g, aromatic ring systems and alkyl-aryl C-C bonds turned to ordered graphitic char. The pores massively generated from S4 to S5, while micropores partly formed to larger and mesopores+macropores fractionally converting to smaller from S5 to S6. Besides, both S 2p_3/2 and S 2p_5/2 (sulphone bridge) were enriched after S5. Furthermore, the key structural parameters for huge improvement of specific capacitance were found and it further revealed that mesopores+macropores possessed stronger promotion effect than micropores and S 2p_3/2 was more beneficial than S 2p_5/2.

【 授权许可】

Unknown